Armed factions close to Iran have threatened to attack US interests over Washington's support for Israel since Hamas militants killed more than 1,400 people in a shock cross-border attack from Gaza on October 7.

Israel's retaliatory bombardment of Gaza has killed more than 5,000 people, according to the Gaza health ministry.

"There was an attempted drone attack at Al-Tanf in Syria. Two one-way attack drones taken down; no injuries to US forces," Pentagon spokesman Brigadier General Pat Ryder told journalists.

The drones were downed using "defensive systems," he said, without providing further details.

An American defense official had previously said on condition of anonymity that an attack in Syria had targeted forces from the United States and the international coalition against the Islamic State (IS) jihadist group.

Neither Ryder nor the official provided details on the organization that carried out the attack, but a group calling itself the Islamic Resistance in Iraq said earlier in the day that it had launched drones against American forces at Al-Tanf and Al-Malikiyah in Syria.

The same group also claimed to have targeted US troops in Iraq on Saturday -- an attack the United States said it could not confirm -- while American forces shot down two drones in the country last week.

The United States has some 900 troops in Syria and 2,500 in Iraq as part of efforts to combat IS, which once held significant territory in both countries but was pushed back by local forces supported by international air strikes.